#include <stdio.h>
int main(){
    /*
    sizeof 用来计算变量与常量在内存占用的字节
    sizeof(数据类型)
    sizeof(变量)
    sizeof(常量)
    */
   printf("int占用字节=%lu\n",sizeof(int));
   printf("float占用字节=%lu\n",sizeof(float));
   printf("double占用字节=%lu\n",sizeof(double));
   printf("char占用字节=%lu\n",sizeof(char));
}